Packing device for shafts



Dec. 30, 1941. W. M. KERMODE Em 2,268,281 PACKINQ DEVICE FOR SHAFT-SFiled July 24, 1940 Patented Dec. 30, 1941 UNITED STATES PATENT OFFICEPACKING DEVICE FOR SHAFTS Application July 24, 1940, Serial No..347,322In `Great Britain May 23, 1939 4 Claims.

segments, the internal diameter of which is A equal to the externaldiameter of the shaft, means being provided to retract said segmentsint-o the said recesses or to displace them therein into contact withthe shaft.

'I'he invention is more particularly described with reference to theaccompanying drawing, in which:

Fig. 1 is a sectional elevation of one form of construction on the lineA-A of Fig. 2.

Fig. 2 is an end View partly in section,

Fig. 3 is a detail.

A rotary shaft l is supported in any form of bearing carried by ahousing 3. On this housing, by means of bolts passing through bolt holes4, a casing 5 is mounted which has a number of radial sockets orperforations, in each of which is mounted a displaceable spindle 6provided with a mushroom-headed end I engaging within an open socket 8in part annular segments 9, I0', Il, I2, respectively. One side of themushroom head I has a attened portion engaging a segment to prevent therotation of the spindle 6 relatively to the segments.

Normally the segments will be drawn bac-k out of contact with the shaftinto the position shown in chain dotted lines in Fig. 2 of the drawing,when a valve seating I3 on the spindle 6 comes against the seating i4 inthe casing 5, and this prevents leakage of iiuid from the space I5surrounding the shaft by the sockets or perforations in the casing 5.

When, however, it is desired to effect a temporary seal on the shaft I,for instance when it is desired to dismantle for replacement orinspection the main bearing element including such parts as I6, I'I, thespindles 6 are thrust radially inwardly by screwing down a threadedsleeve I8 until each segment 9, I0, Il, I2,=contacts with the shaft I.When the segments are being retracted the sleeves I8 abut against a nutI9 locked by a pin 20.

the shaft, it will be desirable to cause the segments 9, l0, first toengage with the shaft and then subsequently the segments Il, I2.

As 'shown in Fig. 2 of the drawing, it will be preferred that two of thesegments such as 9, I0, have their ends parallel to the axis `ofdisplacement of the spindles 6, whilst the other two segments Il, I2,have their ends 2|, 22, respectively, at right angles to the axis oftheir spindles 6. By this means the tight packing of the segments on theshaft I is possible.

When all the segments are in position it is obvious that no iiuid in thespace I5 can escape, and thus the main packing can be dismantled andreplaced, either with the shaft stationary or with this running,although it will be desirable to reduce the time of running of the shaftI with the segments in position as much as possible.

In an alternative arrangement the segments may be provided with adovetail or T-shaped groove into which the mushroom headed spindle headwith its flattened sides can be slid from one end; the segment isthereby rmly attached to the pin, .but is capable of rocking slightlyrelatively to it.

Instead of having one group of segments as shown in Fig. 1, two groupsof segments may be provided in parallel planes.

The normal bearing or packing gland may be of any desired type, that isto say it may either consist of a soft packing or a spherical packing,in which case the element I6 of the spherical packing, as illustrated inFig. 1 by way of example, may co-operate with a spherical surface on thecasing 5 of the device.

As the segments are only temporarily in contact with the shaft a perfectpacking can always be temporarily maintained between segments and theshaft.

If desired powerful springs may be interposed between the segments andthe spindles to hold the segments elastically in contact with the shaft.

It will -be appreciated that three or any higher number of segments maybe utilised without departing from the scope of the invention and thatthe inner bearing surfaces of the segments, where these cooperate withthe shaft for preventing leakage along the latter, are -of rigidmaterial.

We declare that what we claim is:

1. A packing device for shafts comprising a power shaft, a fixed casingencircling the shaft In bringing the device into operation, to seal andhaving at least three radial recesses therein,

a corresponding number of arcuate segments each subtending an arc of notmore than 120 and providing an internal rigid bearing surface of adiameter equal to the externa-l diameter of the shaft, a correspondingnumber of spindles one disposed in each of the said recesses, each ofsaid spindles having a mushroom head engaging a corresponding segmentand each mushl room head having a flattened surface engaging thecorresponding segment whereby `to prevent rotation of the spindlerelative to'the segment, and means for displacing said spindles radiallyof the shaft whereby to shift lthe segments into and out of engagementwith Vthe shaft.

2. A packing device for shafts comprisingaY power shaft, a xed casingencircling the shaft and having at least three radial recesses therein;

a corresponding number of annular -segments each subtending an arc ofnot more than .120

with a rigid .bearing surface of arcuate formv lateral adjustment ofeach segment relatively to its spindle, and means for displacing eachspindle and its segment as a unit radially of said casing.

3. A packing device for shafts comprising a power shaft, a fixed casingencircling said shaft, four spindles guided radially in said Icasing,four annular segments each connected to a .corresponding spindle fordisplacement therewith radially of the casing but with limited lateralplay, two opposed segments having their end surfaces parallel to theaxes of their respective spindles and the other two opposed segmentshavingtheir end surfaces at right angles to their respective spindlesand each of said segments having an internal curvature complemental toVthe'external contour of the shaft, and means forldisplacing thespindles with the segmentsradially of the casing.

4. A packing device for shafts, as `claimed in claim 3, and wherein eachspindleis non-rotatably guided in a radial recess in the fixed casingand has means for sealing vsaid recess" against outward 'ow of liquidfrom the shaft peripheryl WILLIAM MARSDEN KERMODE EDITH ISOBEL` HOWARD,

Eecutrz' of the Estate of John Howard,A 'De, ceased. 2.1 "Y: f

